1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */ 3 4 #include <linux/bpf.h> 5 #include <linux/btf_ids.h> 6 #include <linux/filter.h> 7 #include <linux/errno.h> 8 #include <linux/file.h> 9 #include <linux/net.h> 10 #include <linux/workqueue.h> 11 #include <linux/skmsg.h> 12 #include <linux/list.h> 13 #include <linux/jhash.h> 14 #include <linux/sock_diag.h> 15 #include <net/udp.h> 16 17 struct bpf_stab { 18 struct bpf_map map; 19 struct sock **sks; 20 struct sk_psock_progs progs; 21 raw_spinlock_t lock; 22 }; 23 24 #define SOCK_CREATE_FLAG_MASK \ 25 (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) 26 27 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, 28 struct bpf_prog *old, u32 which); 29 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map); 30 31 static struct bpf_map *sock_map_alloc(union bpf_attr *attr) 32 { 33 struct bpf_stab *stab; 34 35 if (!capable(CAP_NET_ADMIN)) 36 return ERR_PTR(-EPERM); 37 if (attr->max_entries == 0 || 38 attr->key_size != 4 || 39 (attr->value_size != sizeof(u32) && 40 attr->value_size != sizeof(u64)) || 41 attr->map_flags & ~SOCK_CREATE_FLAG_MASK) 42 return ERR_PTR(-EINVAL); 43 44 stab = bpf_map_area_alloc(sizeof(*stab), NUMA_NO_NODE); 45 if (!stab) 46 return ERR_PTR(-ENOMEM); 47 48 bpf_map_init_from_attr(&stab->map, attr); 49 raw_spin_lock_init(&stab->lock); 50 51 stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries * 52 sizeof(struct sock *), 53 stab->map.numa_node); 54 if (!stab->sks) { 55 bpf_map_area_free(stab); 56 return ERR_PTR(-ENOMEM); 57 } 58 59 return &stab->map; 60 } 61 62 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog) 63 { 64 u32 ufd = attr->target_fd; 65 struct bpf_map *map; 66 struct fd f; 67 int ret; 68 69 if (attr->attach_flags || attr->replace_bpf_fd) 70 return -EINVAL; 71 72 f = fdget(ufd); 73 map = __bpf_map_get(f); 74 if (IS_ERR(map)) 75 return PTR_ERR(map); 76 ret = sock_map_prog_update(map, prog, NULL, attr->attach_type); 77 fdput(f); 78 return ret; 79 } 80 81 int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype) 82 { 83 u32 ufd = attr->target_fd; 84 struct bpf_prog *prog; 85 struct bpf_map *map; 86 struct fd f; 87 int ret; 88 89 if (attr->attach_flags || attr->replace_bpf_fd) 90 return -EINVAL; 91 92 f = fdget(ufd); 93 map = __bpf_map_get(f); 94 if (IS_ERR(map)) 95 return PTR_ERR(map); 96 97 prog = bpf_prog_get(attr->attach_bpf_fd); 98 if (IS_ERR(prog)) { 99 ret = PTR_ERR(prog); 100 goto put_map; 101 } 102 103 if (prog->type != ptype) { 104 ret = -EINVAL; 105 goto put_prog; 106 } 107 108 ret = sock_map_prog_update(map, NULL, prog, attr->attach_type); 109 put_prog: 110 bpf_prog_put(prog); 111 put_map: 112 fdput(f); 113 return ret; 114 } 115 116 static void sock_map_sk_acquire(struct sock *sk) 117 __acquires(&sk->sk_lock.slock) 118 { 119 lock_sock(sk); 120 preempt_disable(); 121 rcu_read_lock(); 122 } 123 124 static void sock_map_sk_release(struct sock *sk) 125 __releases(&sk->sk_lock.slock) 126 { 127 rcu_read_unlock(); 128 preempt_enable(); 129 release_sock(sk); 130 } 131 132 static void sock_map_add_link(struct sk_psock *psock, 133 struct sk_psock_link *link, 134 struct bpf_map *map, void *link_raw) 135 { 136 link->link_raw = link_raw; 137 link->map = map; 138 spin_lock_bh(&psock->link_lock); 139 list_add_tail(&link->list, &psock->link); 140 spin_unlock_bh(&psock->link_lock); 141 } 142 143 static void sock_map_del_link(struct sock *sk, 144 struct sk_psock *psock, void *link_raw) 145 { 146 bool strp_stop = false, verdict_stop = false; 147 struct sk_psock_link *link, *tmp; 148 149 spin_lock_bh(&psock->link_lock); 150 list_for_each_entry_safe(link, tmp, &psock->link, list) { 151 if (link->link_raw == link_raw) { 152 struct bpf_map *map = link->map; 153 struct bpf_stab *stab = container_of(map, struct bpf_stab, 154 map); 155 if (psock->saved_data_ready && stab->progs.stream_parser) 156 strp_stop = true; 157 if (psock->saved_data_ready && stab->progs.stream_verdict) 158 verdict_stop = true; 159 if (psock->saved_data_ready && stab->progs.skb_verdict) 160 verdict_stop = true; 161 list_del(&link->list); 162 sk_psock_free_link(link); 163 } 164 } 165 spin_unlock_bh(&psock->link_lock); 166 if (strp_stop || verdict_stop) { 167 write_lock_bh(&sk->sk_callback_lock); 168 if (strp_stop) 169 sk_psock_stop_strp(sk, psock); 170 if (verdict_stop) 171 sk_psock_stop_verdict(sk, psock); 172 173 if (psock->psock_update_sk_prot) 174 psock->psock_update_sk_prot(sk, psock, false); 175 write_unlock_bh(&sk->sk_callback_lock); 176 } 177 } 178 179 static void sock_map_unref(struct sock *sk, void *link_raw) 180 { 181 struct sk_psock *psock = sk_psock(sk); 182 183 if (likely(psock)) { 184 sock_map_del_link(sk, psock, link_raw); 185 sk_psock_put(sk, psock); 186 } 187 } 188 189 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock) 190 { 191 if (!sk->sk_prot->psock_update_sk_prot) 192 return -EINVAL; 193 psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot; 194 return sk->sk_prot->psock_update_sk_prot(sk, psock, false); 195 } 196 197 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk) 198 { 199 struct sk_psock *psock; 200 201 rcu_read_lock(); 202 psock = sk_psock(sk); 203 if (psock) { 204 if (sk->sk_prot->close != sock_map_close) { 205 psock = ERR_PTR(-EBUSY); 206 goto out; 207 } 208 209 if (!refcount_inc_not_zero(&psock->refcnt)) 210 psock = ERR_PTR(-EBUSY); 211 } 212 out: 213 rcu_read_unlock(); 214 return psock; 215 } 216 217 static int sock_map_link(struct bpf_map *map, struct sock *sk) 218 { 219 struct sk_psock_progs *progs = sock_map_progs(map); 220 struct bpf_prog *stream_verdict = NULL; 221 struct bpf_prog *stream_parser = NULL; 222 struct bpf_prog *skb_verdict = NULL; 223 struct bpf_prog *msg_parser = NULL; 224 struct sk_psock *psock; 225 int ret; 226 227 stream_verdict = READ_ONCE(progs->stream_verdict); 228 if (stream_verdict) { 229 stream_verdict = bpf_prog_inc_not_zero(stream_verdict); 230 if (IS_ERR(stream_verdict)) 231 return PTR_ERR(stream_verdict); 232 } 233 234 stream_parser = READ_ONCE(progs->stream_parser); 235 if (stream_parser) { 236 stream_parser = bpf_prog_inc_not_zero(stream_parser); 237 if (IS_ERR(stream_parser)) { 238 ret = PTR_ERR(stream_parser); 239 goto out_put_stream_verdict; 240 } 241 } 242 243 msg_parser = READ_ONCE(progs->msg_parser); 244 if (msg_parser) { 245 msg_parser = bpf_prog_inc_not_zero(msg_parser); 246 if (IS_ERR(msg_parser)) { 247 ret = PTR_ERR(msg_parser); 248 goto out_put_stream_parser; 249 } 250 } 251 252 skb_verdict = READ_ONCE(progs->skb_verdict); 253 if (skb_verdict) { 254 skb_verdict = bpf_prog_inc_not_zero(skb_verdict); 255 if (IS_ERR(skb_verdict)) { 256 ret = PTR_ERR(skb_verdict); 257 goto out_put_msg_parser; 258 } 259 } 260 261 psock = sock_map_psock_get_checked(sk); 262 if (IS_ERR(psock)) { 263 ret = PTR_ERR(psock); 264 goto out_progs; 265 } 266 267 if (psock) { 268 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) || 269 (stream_parser && READ_ONCE(psock->progs.stream_parser)) || 270 (skb_verdict && READ_ONCE(psock->progs.skb_verdict)) || 271 (skb_verdict && READ_ONCE(psock->progs.stream_verdict)) || 272 (stream_verdict && READ_ONCE(psock->progs.skb_verdict)) || 273 (stream_verdict && READ_ONCE(psock->progs.stream_verdict))) { 274 sk_psock_put(sk, psock); 275 ret = -EBUSY; 276 goto out_progs; 277 } 278 } else { 279 psock = sk_psock_init(sk, map->numa_node); 280 if (IS_ERR(psock)) { 281 ret = PTR_ERR(psock); 282 goto out_progs; 283 } 284 } 285 286 if (msg_parser) 287 psock_set_prog(&psock->progs.msg_parser, msg_parser); 288 if (stream_parser) 289 psock_set_prog(&psock->progs.stream_parser, stream_parser); 290 if (stream_verdict) 291 psock_set_prog(&psock->progs.stream_verdict, stream_verdict); 292 if (skb_verdict) 293 psock_set_prog(&psock->progs.skb_verdict, skb_verdict); 294 295 /* msg_* and stream_* programs references tracked in psock after this 296 * point. Reference dec and cleanup will occur through psock destructor 297 */ 298 ret = sock_map_init_proto(sk, psock); 299 if (ret < 0) { 300 sk_psock_put(sk, psock); 301 goto out; 302 } 303 304 write_lock_bh(&sk->sk_callback_lock); 305 if (stream_parser && stream_verdict && !psock->saved_data_ready) { 306 ret = sk_psock_init_strp(sk, psock); 307 if (ret) { 308 write_unlock_bh(&sk->sk_callback_lock); 309 sk_psock_put(sk, psock); 310 goto out; 311 } 312 sk_psock_start_strp(sk, psock); 313 } else if (!stream_parser && stream_verdict && !psock->saved_data_ready) { 314 sk_psock_start_verdict(sk,psock); 315 } else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) { 316 sk_psock_start_verdict(sk, psock); 317 } 318 write_unlock_bh(&sk->sk_callback_lock); 319 return 0; 320 out_progs: 321 if (skb_verdict) 322 bpf_prog_put(skb_verdict); 323 out_put_msg_parser: 324 if (msg_parser) 325 bpf_prog_put(msg_parser); 326 out_put_stream_parser: 327 if (stream_parser) 328 bpf_prog_put(stream_parser); 329 out_put_stream_verdict: 330 if (stream_verdict) 331 bpf_prog_put(stream_verdict); 332 out: 333 return ret; 334 } 335 336 static void sock_map_free(struct bpf_map *map) 337 { 338 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 339 int i; 340 341 /* After the sync no updates or deletes will be in-flight so it 342 * is safe to walk map and remove entries without risking a race 343 * in EEXIST update case. 344 */ 345 synchronize_rcu(); 346 for (i = 0; i < stab->map.max_entries; i++) { 347 struct sock **psk = &stab->sks[i]; 348 struct sock *sk; 349 350 sk = xchg(psk, NULL); 351 if (sk) { 352 sock_hold(sk); 353 lock_sock(sk); 354 rcu_read_lock(); 355 sock_map_unref(sk, psk); 356 rcu_read_unlock(); 357 release_sock(sk); 358 sock_put(sk); 359 } 360 } 361 362 /* wait for psock readers accessing its map link */ 363 synchronize_rcu(); 364 365 bpf_map_area_free(stab->sks); 366 bpf_map_area_free(stab); 367 } 368 369 static void sock_map_release_progs(struct bpf_map *map) 370 { 371 psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs); 372 } 373 374 static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key) 375 { 376 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 377 378 WARN_ON_ONCE(!rcu_read_lock_held()); 379 380 if (unlikely(key >= map->max_entries)) 381 return NULL; 382 return READ_ONCE(stab->sks[key]); 383 } 384 385 static void *sock_map_lookup(struct bpf_map *map, void *key) 386 { 387 struct sock *sk; 388 389 sk = __sock_map_lookup_elem(map, *(u32 *)key); 390 if (!sk) 391 return NULL; 392 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt)) 393 return NULL; 394 return sk; 395 } 396 397 static void *sock_map_lookup_sys(struct bpf_map *map, void *key) 398 { 399 struct sock *sk; 400 401 if (map->value_size != sizeof(u64)) 402 return ERR_PTR(-ENOSPC); 403 404 sk = __sock_map_lookup_elem(map, *(u32 *)key); 405 if (!sk) 406 return ERR_PTR(-ENOENT); 407 408 __sock_gen_cookie(sk); 409 return &sk->sk_cookie; 410 } 411 412 static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test, 413 struct sock **psk) 414 { 415 struct sock *sk; 416 int err = 0; 417 418 raw_spin_lock_bh(&stab->lock); 419 sk = *psk; 420 if (!sk_test || sk_test == sk) 421 sk = xchg(psk, NULL); 422 423 if (likely(sk)) 424 sock_map_unref(sk, psk); 425 else 426 err = -EINVAL; 427 428 raw_spin_unlock_bh(&stab->lock); 429 return err; 430 } 431 432 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk, 433 void *link_raw) 434 { 435 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 436 437 __sock_map_delete(stab, sk, link_raw); 438 } 439 440 static long sock_map_delete_elem(struct bpf_map *map, void *key) 441 { 442 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 443 u32 i = *(u32 *)key; 444 struct sock **psk; 445 446 if (unlikely(i >= map->max_entries)) 447 return -EINVAL; 448 449 psk = &stab->sks[i]; 450 return __sock_map_delete(stab, NULL, psk); 451 } 452 453 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next) 454 { 455 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 456 u32 i = key ? *(u32 *)key : U32_MAX; 457 u32 *key_next = next; 458 459 if (i == stab->map.max_entries - 1) 460 return -ENOENT; 461 if (i >= stab->map.max_entries) 462 *key_next = 0; 463 else 464 *key_next = i + 1; 465 return 0; 466 } 467 468 static int sock_map_update_common(struct bpf_map *map, u32 idx, 469 struct sock *sk, u64 flags) 470 { 471 struct bpf_stab *stab = container_of(map, struct bpf_stab, map); 472 struct sk_psock_link *link; 473 struct sk_psock *psock; 474 struct sock *osk; 475 int ret; 476 477 WARN_ON_ONCE(!rcu_read_lock_held()); 478 if (unlikely(flags > BPF_EXIST)) 479 return -EINVAL; 480 if (unlikely(idx >= map->max_entries)) 481 return -E2BIG; 482 483 link = sk_psock_init_link(); 484 if (!link) 485 return -ENOMEM; 486 487 ret = sock_map_link(map, sk); 488 if (ret < 0) 489 goto out_free; 490 491 psock = sk_psock(sk); 492 WARN_ON_ONCE(!psock); 493 494 raw_spin_lock_bh(&stab->lock); 495 osk = stab->sks[idx]; 496 if (osk && flags == BPF_NOEXIST) { 497 ret = -EEXIST; 498 goto out_unlock; 499 } else if (!osk && flags == BPF_EXIST) { 500 ret = -ENOENT; 501 goto out_unlock; 502 } 503 504 sock_map_add_link(psock, link, map, &stab->sks[idx]); 505 stab->sks[idx] = sk; 506 if (osk) 507 sock_map_unref(osk, &stab->sks[idx]); 508 raw_spin_unlock_bh(&stab->lock); 509 return 0; 510 out_unlock: 511 raw_spin_unlock_bh(&stab->lock); 512 if (psock) 513 sk_psock_put(sk, psock); 514 out_free: 515 sk_psock_free_link(link); 516 return ret; 517 } 518 519 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops) 520 { 521 return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB || 522 ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB || 523 ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB; 524 } 525 526 static bool sock_map_redirect_allowed(const struct sock *sk) 527 { 528 if (sk_is_tcp(sk)) 529 return sk->sk_state != TCP_LISTEN; 530 else 531 return sk->sk_state == TCP_ESTABLISHED; 532 } 533 534 static bool sock_map_sk_is_suitable(const struct sock *sk) 535 { 536 return !!sk->sk_prot->psock_update_sk_prot; 537 } 538 539 static bool sock_map_sk_state_allowed(const struct sock *sk) 540 { 541 if (sk_is_tcp(sk)) 542 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN); 543 return true; 544 } 545 546 static int sock_hash_update_common(struct bpf_map *map, void *key, 547 struct sock *sk, u64 flags); 548 549 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value, 550 u64 flags) 551 { 552 struct socket *sock; 553 struct sock *sk; 554 int ret; 555 u64 ufd; 556 557 if (map->value_size == sizeof(u64)) 558 ufd = *(u64 *)value; 559 else 560 ufd = *(u32 *)value; 561 if (ufd > S32_MAX) 562 return -EINVAL; 563 564 sock = sockfd_lookup(ufd, &ret); 565 if (!sock) 566 return ret; 567 sk = sock->sk; 568 if (!sk) { 569 ret = -EINVAL; 570 goto out; 571 } 572 if (!sock_map_sk_is_suitable(sk)) { 573 ret = -EOPNOTSUPP; 574 goto out; 575 } 576 577 sock_map_sk_acquire(sk); 578 if (!sock_map_sk_state_allowed(sk)) 579 ret = -EOPNOTSUPP; 580 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP) 581 ret = sock_map_update_common(map, *(u32 *)key, sk, flags); 582 else 583 ret = sock_hash_update_common(map, key, sk, flags); 584 sock_map_sk_release(sk); 585 out: 586 sockfd_put(sock); 587 return ret; 588 } 589 590 static long sock_map_update_elem(struct bpf_map *map, void *key, 591 void *value, u64 flags) 592 { 593 struct sock *sk = (struct sock *)value; 594 int ret; 595 596 if (unlikely(!sk || !sk_fullsock(sk))) 597 return -EINVAL; 598 599 if (!sock_map_sk_is_suitable(sk)) 600 return -EOPNOTSUPP; 601 602 local_bh_disable(); 603 bh_lock_sock(sk); 604 if (!sock_map_sk_state_allowed(sk)) 605 ret = -EOPNOTSUPP; 606 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP) 607 ret = sock_map_update_common(map, *(u32 *)key, sk, flags); 608 else 609 ret = sock_hash_update_common(map, key, sk, flags); 610 bh_unlock_sock(sk); 611 local_bh_enable(); 612 return ret; 613 } 614 615 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops, 616 struct bpf_map *, map, void *, key, u64, flags) 617 { 618 WARN_ON_ONCE(!rcu_read_lock_held()); 619 620 if (likely(sock_map_sk_is_suitable(sops->sk) && 621 sock_map_op_okay(sops))) 622 return sock_map_update_common(map, *(u32 *)key, sops->sk, 623 flags); 624 return -EOPNOTSUPP; 625 } 626 627 const struct bpf_func_proto bpf_sock_map_update_proto = { 628 .func = bpf_sock_map_update, 629 .gpl_only = false, 630 .pkt_access = true, 631 .ret_type = RET_INTEGER, 632 .arg1_type = ARG_PTR_TO_CTX, 633 .arg2_type = ARG_CONST_MAP_PTR, 634 .arg3_type = ARG_PTR_TO_MAP_KEY, 635 .arg4_type = ARG_ANYTHING, 636 }; 637 638 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb, 639 struct bpf_map *, map, u32, key, u64, flags) 640 { 641 struct sock *sk; 642 643 if (unlikely(flags & ~(BPF_F_INGRESS))) 644 return SK_DROP; 645 646 sk = __sock_map_lookup_elem(map, key); 647 if (unlikely(!sk || !sock_map_redirect_allowed(sk))) 648 return SK_DROP; 649 650 skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS); 651 return SK_PASS; 652 } 653 654 const struct bpf_func_proto bpf_sk_redirect_map_proto = { 655 .func = bpf_sk_redirect_map, 656 .gpl_only = false, 657 .ret_type = RET_INTEGER, 658 .arg1_type = ARG_PTR_TO_CTX, 659 .arg2_type = ARG_CONST_MAP_PTR, 660 .arg3_type = ARG_ANYTHING, 661 .arg4_type = ARG_ANYTHING, 662 }; 663 664 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg, 665 struct bpf_map *, map, u32, key, u64, flags) 666 { 667 struct sock *sk; 668 669 if (unlikely(flags & ~(BPF_F_INGRESS))) 670 return SK_DROP; 671 672 sk = __sock_map_lookup_elem(map, key); 673 if (unlikely(!sk || !sock_map_redirect_allowed(sk))) 674 return SK_DROP; 675 676 msg->flags = flags; 677 msg->sk_redir = sk; 678 return SK_PASS; 679 } 680 681 const struct bpf_func_proto bpf_msg_redirect_map_proto = { 682 .func = bpf_msg_redirect_map, 683 .gpl_only = false, 684 .ret_type = RET_INTEGER, 685 .arg1_type = ARG_PTR_TO_CTX, 686 .arg2_type = ARG_CONST_MAP_PTR, 687 .arg3_type = ARG_ANYTHING, 688 .arg4_type = ARG_ANYTHING, 689 }; 690 691 struct sock_map_seq_info { 692 struct bpf_map *map; 693 struct sock *sk; 694 u32 index; 695 }; 696 697 struct bpf_iter__sockmap { 698 __bpf_md_ptr(struct bpf_iter_meta *, meta); 699 __bpf_md_ptr(struct bpf_map *, map); 700 __bpf_md_ptr(void *, key); 701 __bpf_md_ptr(struct sock *, sk); 702 }; 703 704 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta, 705 struct bpf_map *map, void *key, 706 struct sock *sk) 707 708 static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info) 709 { 710 if (unlikely(info->index >= info->map->max_entries)) 711 return NULL; 712 713 info->sk = __sock_map_lookup_elem(info->map, info->index); 714 715 /* can't return sk directly, since that might be NULL */ 716 return info; 717 } 718 719 static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos) 720 __acquires(rcu) 721 { 722 struct sock_map_seq_info *info = seq->private; 723 724 if (*pos == 0) 725 ++*pos; 726 727 /* pairs with sock_map_seq_stop */ 728 rcu_read_lock(); 729 return sock_map_seq_lookup_elem(info); 730 } 731 732 static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos) 733 __must_hold(rcu) 734 { 735 struct sock_map_seq_info *info = seq->private; 736 737 ++*pos; 738 ++info->index; 739 740 return sock_map_seq_lookup_elem(info); 741 } 742 743 static int sock_map_seq_show(struct seq_file *seq, void *v) 744 __must_hold(rcu) 745 { 746 struct sock_map_seq_info *info = seq->private; 747 struct bpf_iter__sockmap ctx = {}; 748 struct bpf_iter_meta meta; 749 struct bpf_prog *prog; 750 751 meta.seq = seq; 752 prog = bpf_iter_get_info(&meta, !v); 753 if (!prog) 754 return 0; 755 756 ctx.meta = &meta; 757 ctx.map = info->map; 758 if (v) { 759 ctx.key = &info->index; 760 ctx.sk = info->sk; 761 } 762 763 return bpf_iter_run_prog(prog, &ctx); 764 } 765 766 static void sock_map_seq_stop(struct seq_file *seq, void *v) 767 __releases(rcu) 768 { 769 if (!v) 770 (void)sock_map_seq_show(seq, NULL); 771 772 /* pairs with sock_map_seq_start */ 773 rcu_read_unlock(); 774 } 775 776 static const struct seq_operations sock_map_seq_ops = { 777 .start = sock_map_seq_start, 778 .next = sock_map_seq_next, 779 .stop = sock_map_seq_stop, 780 .show = sock_map_seq_show, 781 }; 782 783 static int sock_map_init_seq_private(void *priv_data, 784 struct bpf_iter_aux_info *aux) 785 { 786 struct sock_map_seq_info *info = priv_data; 787 788 bpf_map_inc_with_uref(aux->map); 789 info->map = aux->map; 790 return 0; 791 } 792 793 static void sock_map_fini_seq_private(void *priv_data) 794 { 795 struct sock_map_seq_info *info = priv_data; 796 797 bpf_map_put_with_uref(info->map); 798 } 799 800 static u64 sock_map_mem_usage(const struct bpf_map *map) 801 { 802 u64 usage = sizeof(struct bpf_stab); 803 804 usage += (u64)map->max_entries * sizeof(struct sock *); 805 return usage; 806 } 807 808 static const struct bpf_iter_seq_info sock_map_iter_seq_info = { 809 .seq_ops = &sock_map_seq_ops, 810 .init_seq_private = sock_map_init_seq_private, 811 .fini_seq_private = sock_map_fini_seq_private, 812 .seq_priv_size = sizeof(struct sock_map_seq_info), 813 }; 814 815 BTF_ID_LIST_SINGLE(sock_map_btf_ids, struct, bpf_stab) 816 const struct bpf_map_ops sock_map_ops = { 817 .map_meta_equal = bpf_map_meta_equal, 818 .map_alloc = sock_map_alloc, 819 .map_free = sock_map_free, 820 .map_get_next_key = sock_map_get_next_key, 821 .map_lookup_elem_sys_only = sock_map_lookup_sys, 822 .map_update_elem = sock_map_update_elem, 823 .map_delete_elem = sock_map_delete_elem, 824 .map_lookup_elem = sock_map_lookup, 825 .map_release_uref = sock_map_release_progs, 826 .map_check_btf = map_check_no_btf, 827 .map_mem_usage = sock_map_mem_usage, 828 .map_btf_id = &sock_map_btf_ids[0], 829 .iter_seq_info = &sock_map_iter_seq_info, 830 }; 831 832 struct bpf_shtab_elem { 833 struct rcu_head rcu; 834 u32 hash; 835 struct sock *sk; 836 struct hlist_node node; 837 u8 key[]; 838 }; 839 840 struct bpf_shtab_bucket { 841 struct hlist_head head; 842 raw_spinlock_t lock; 843 }; 844 845 struct bpf_shtab { 846 struct bpf_map map; 847 struct bpf_shtab_bucket *buckets; 848 u32 buckets_num; 849 u32 elem_size; 850 struct sk_psock_progs progs; 851 atomic_t count; 852 }; 853 854 static inline u32 sock_hash_bucket_hash(const void *key, u32 len) 855 { 856 return jhash(key, len, 0); 857 } 858 859 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab, 860 u32 hash) 861 { 862 return &htab->buckets[hash & (htab->buckets_num - 1)]; 863 } 864 865 static struct bpf_shtab_elem * 866 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key, 867 u32 key_size) 868 { 869 struct bpf_shtab_elem *elem; 870 871 hlist_for_each_entry_rcu(elem, head, node) { 872 if (elem->hash == hash && 873 !memcmp(&elem->key, key, key_size)) 874 return elem; 875 } 876 877 return NULL; 878 } 879 880 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key) 881 { 882 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 883 u32 key_size = map->key_size, hash; 884 struct bpf_shtab_bucket *bucket; 885 struct bpf_shtab_elem *elem; 886 887 WARN_ON_ONCE(!rcu_read_lock_held()); 888 889 hash = sock_hash_bucket_hash(key, key_size); 890 bucket = sock_hash_select_bucket(htab, hash); 891 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); 892 893 return elem ? elem->sk : NULL; 894 } 895 896 static void sock_hash_free_elem(struct bpf_shtab *htab, 897 struct bpf_shtab_elem *elem) 898 { 899 atomic_dec(&htab->count); 900 kfree_rcu(elem, rcu); 901 } 902 903 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk, 904 void *link_raw) 905 { 906 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 907 struct bpf_shtab_elem *elem_probe, *elem = link_raw; 908 struct bpf_shtab_bucket *bucket; 909 910 WARN_ON_ONCE(!rcu_read_lock_held()); 911 bucket = sock_hash_select_bucket(htab, elem->hash); 912 913 /* elem may be deleted in parallel from the map, but access here 914 * is okay since it's going away only after RCU grace period. 915 * However, we need to check whether it's still present. 916 */ 917 raw_spin_lock_bh(&bucket->lock); 918 elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash, 919 elem->key, map->key_size); 920 if (elem_probe && elem_probe == elem) { 921 hlist_del_rcu(&elem->node); 922 sock_map_unref(elem->sk, elem); 923 sock_hash_free_elem(htab, elem); 924 } 925 raw_spin_unlock_bh(&bucket->lock); 926 } 927 928 static long sock_hash_delete_elem(struct bpf_map *map, void *key) 929 { 930 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 931 u32 hash, key_size = map->key_size; 932 struct bpf_shtab_bucket *bucket; 933 struct bpf_shtab_elem *elem; 934 int ret = -ENOENT; 935 936 hash = sock_hash_bucket_hash(key, key_size); 937 bucket = sock_hash_select_bucket(htab, hash); 938 939 raw_spin_lock_bh(&bucket->lock); 940 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); 941 if (elem) { 942 hlist_del_rcu(&elem->node); 943 sock_map_unref(elem->sk, elem); 944 sock_hash_free_elem(htab, elem); 945 ret = 0; 946 } 947 raw_spin_unlock_bh(&bucket->lock); 948 return ret; 949 } 950 951 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab, 952 void *key, u32 key_size, 953 u32 hash, struct sock *sk, 954 struct bpf_shtab_elem *old) 955 { 956 struct bpf_shtab_elem *new; 957 958 if (atomic_inc_return(&htab->count) > htab->map.max_entries) { 959 if (!old) { 960 atomic_dec(&htab->count); 961 return ERR_PTR(-E2BIG); 962 } 963 } 964 965 new = bpf_map_kmalloc_node(&htab->map, htab->elem_size, 966 GFP_ATOMIC | __GFP_NOWARN, 967 htab->map.numa_node); 968 if (!new) { 969 atomic_dec(&htab->count); 970 return ERR_PTR(-ENOMEM); 971 } 972 memcpy(new->key, key, key_size); 973 new->sk = sk; 974 new->hash = hash; 975 return new; 976 } 977 978 static int sock_hash_update_common(struct bpf_map *map, void *key, 979 struct sock *sk, u64 flags) 980 { 981 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 982 u32 key_size = map->key_size, hash; 983 struct bpf_shtab_elem *elem, *elem_new; 984 struct bpf_shtab_bucket *bucket; 985 struct sk_psock_link *link; 986 struct sk_psock *psock; 987 int ret; 988 989 WARN_ON_ONCE(!rcu_read_lock_held()); 990 if (unlikely(flags > BPF_EXIST)) 991 return -EINVAL; 992 993 link = sk_psock_init_link(); 994 if (!link) 995 return -ENOMEM; 996 997 ret = sock_map_link(map, sk); 998 if (ret < 0) 999 goto out_free; 1000 1001 psock = sk_psock(sk); 1002 WARN_ON_ONCE(!psock); 1003 1004 hash = sock_hash_bucket_hash(key, key_size); 1005 bucket = sock_hash_select_bucket(htab, hash); 1006 1007 raw_spin_lock_bh(&bucket->lock); 1008 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); 1009 if (elem && flags == BPF_NOEXIST) { 1010 ret = -EEXIST; 1011 goto out_unlock; 1012 } else if (!elem && flags == BPF_EXIST) { 1013 ret = -ENOENT; 1014 goto out_unlock; 1015 } 1016 1017 elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem); 1018 if (IS_ERR(elem_new)) { 1019 ret = PTR_ERR(elem_new); 1020 goto out_unlock; 1021 } 1022 1023 sock_map_add_link(psock, link, map, elem_new); 1024 /* Add new element to the head of the list, so that 1025 * concurrent search will find it before old elem. 1026 */ 1027 hlist_add_head_rcu(&elem_new->node, &bucket->head); 1028 if (elem) { 1029 hlist_del_rcu(&elem->node); 1030 sock_map_unref(elem->sk, elem); 1031 sock_hash_free_elem(htab, elem); 1032 } 1033 raw_spin_unlock_bh(&bucket->lock); 1034 return 0; 1035 out_unlock: 1036 raw_spin_unlock_bh(&bucket->lock); 1037 sk_psock_put(sk, psock); 1038 out_free: 1039 sk_psock_free_link(link); 1040 return ret; 1041 } 1042 1043 static int sock_hash_get_next_key(struct bpf_map *map, void *key, 1044 void *key_next) 1045 { 1046 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 1047 struct bpf_shtab_elem *elem, *elem_next; 1048 u32 hash, key_size = map->key_size; 1049 struct hlist_head *head; 1050 int i = 0; 1051 1052 if (!key) 1053 goto find_first_elem; 1054 hash = sock_hash_bucket_hash(key, key_size); 1055 head = &sock_hash_select_bucket(htab, hash)->head; 1056 elem = sock_hash_lookup_elem_raw(head, hash, key, key_size); 1057 if (!elem) 1058 goto find_first_elem; 1059 1060 elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)), 1061 struct bpf_shtab_elem, node); 1062 if (elem_next) { 1063 memcpy(key_next, elem_next->key, key_size); 1064 return 0; 1065 } 1066 1067 i = hash & (htab->buckets_num - 1); 1068 i++; 1069 find_first_elem: 1070 for (; i < htab->buckets_num; i++) { 1071 head = &sock_hash_select_bucket(htab, i)->head; 1072 elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)), 1073 struct bpf_shtab_elem, node); 1074 if (elem_next) { 1075 memcpy(key_next, elem_next->key, key_size); 1076 return 0; 1077 } 1078 } 1079 1080 return -ENOENT; 1081 } 1082 1083 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) 1084 { 1085 struct bpf_shtab *htab; 1086 int i, err; 1087 1088 if (!capable(CAP_NET_ADMIN)) 1089 return ERR_PTR(-EPERM); 1090 if (attr->max_entries == 0 || 1091 attr->key_size == 0 || 1092 (attr->value_size != sizeof(u32) && 1093 attr->value_size != sizeof(u64)) || 1094 attr->map_flags & ~SOCK_CREATE_FLAG_MASK) 1095 return ERR_PTR(-EINVAL); 1096 if (attr->key_size > MAX_BPF_STACK) 1097 return ERR_PTR(-E2BIG); 1098 1099 htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE); 1100 if (!htab) 1101 return ERR_PTR(-ENOMEM); 1102 1103 bpf_map_init_from_attr(&htab->map, attr); 1104 1105 htab->buckets_num = roundup_pow_of_two(htab->map.max_entries); 1106 htab->elem_size = sizeof(struct bpf_shtab_elem) + 1107 round_up(htab->map.key_size, 8); 1108 if (htab->buckets_num == 0 || 1109 htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) { 1110 err = -EINVAL; 1111 goto free_htab; 1112 } 1113 1114 htab->buckets = bpf_map_area_alloc(htab->buckets_num * 1115 sizeof(struct bpf_shtab_bucket), 1116 htab->map.numa_node); 1117 if (!htab->buckets) { 1118 err = -ENOMEM; 1119 goto free_htab; 1120 } 1121 1122 for (i = 0; i < htab->buckets_num; i++) { 1123 INIT_HLIST_HEAD(&htab->buckets[i].head); 1124 raw_spin_lock_init(&htab->buckets[i].lock); 1125 } 1126 1127 return &htab->map; 1128 free_htab: 1129 bpf_map_area_free(htab); 1130 return ERR_PTR(err); 1131 } 1132 1133 static void sock_hash_free(struct bpf_map *map) 1134 { 1135 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 1136 struct bpf_shtab_bucket *bucket; 1137 struct hlist_head unlink_list; 1138 struct bpf_shtab_elem *elem; 1139 struct hlist_node *node; 1140 int i; 1141 1142 /* After the sync no updates or deletes will be in-flight so it 1143 * is safe to walk map and remove entries without risking a race 1144 * in EEXIST update case. 1145 */ 1146 synchronize_rcu(); 1147 for (i = 0; i < htab->buckets_num; i++) { 1148 bucket = sock_hash_select_bucket(htab, i); 1149 1150 /* We are racing with sock_hash_delete_from_link to 1151 * enter the spin-lock critical section. Every socket on 1152 * the list is still linked to sockhash. Since link 1153 * exists, psock exists and holds a ref to socket. That 1154 * lets us to grab a socket ref too. 1155 */ 1156 raw_spin_lock_bh(&bucket->lock); 1157 hlist_for_each_entry(elem, &bucket->head, node) 1158 sock_hold(elem->sk); 1159 hlist_move_list(&bucket->head, &unlink_list); 1160 raw_spin_unlock_bh(&bucket->lock); 1161 1162 /* Process removed entries out of atomic context to 1163 * block for socket lock before deleting the psock's 1164 * link to sockhash. 1165 */ 1166 hlist_for_each_entry_safe(elem, node, &unlink_list, node) { 1167 hlist_del(&elem->node); 1168 lock_sock(elem->sk); 1169 rcu_read_lock(); 1170 sock_map_unref(elem->sk, elem); 1171 rcu_read_unlock(); 1172 release_sock(elem->sk); 1173 sock_put(elem->sk); 1174 sock_hash_free_elem(htab, elem); 1175 } 1176 } 1177 1178 /* wait for psock readers accessing its map link */ 1179 synchronize_rcu(); 1180 1181 bpf_map_area_free(htab->buckets); 1182 bpf_map_area_free(htab); 1183 } 1184 1185 static void *sock_hash_lookup_sys(struct bpf_map *map, void *key) 1186 { 1187 struct sock *sk; 1188 1189 if (map->value_size != sizeof(u64)) 1190 return ERR_PTR(-ENOSPC); 1191 1192 sk = __sock_hash_lookup_elem(map, key); 1193 if (!sk) 1194 return ERR_PTR(-ENOENT); 1195 1196 __sock_gen_cookie(sk); 1197 return &sk->sk_cookie; 1198 } 1199 1200 static void *sock_hash_lookup(struct bpf_map *map, void *key) 1201 { 1202 struct sock *sk; 1203 1204 sk = __sock_hash_lookup_elem(map, key); 1205 if (!sk) 1206 return NULL; 1207 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt)) 1208 return NULL; 1209 return sk; 1210 } 1211 1212 static void sock_hash_release_progs(struct bpf_map *map) 1213 { 1214 psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs); 1215 } 1216 1217 BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops, 1218 struct bpf_map *, map, void *, key, u64, flags) 1219 { 1220 WARN_ON_ONCE(!rcu_read_lock_held()); 1221 1222 if (likely(sock_map_sk_is_suitable(sops->sk) && 1223 sock_map_op_okay(sops))) 1224 return sock_hash_update_common(map, key, sops->sk, flags); 1225 return -EOPNOTSUPP; 1226 } 1227 1228 const struct bpf_func_proto bpf_sock_hash_update_proto = { 1229 .func = bpf_sock_hash_update, 1230 .gpl_only = false, 1231 .pkt_access = true, 1232 .ret_type = RET_INTEGER, 1233 .arg1_type = ARG_PTR_TO_CTX, 1234 .arg2_type = ARG_CONST_MAP_PTR, 1235 .arg3_type = ARG_PTR_TO_MAP_KEY, 1236 .arg4_type = ARG_ANYTHING, 1237 }; 1238 1239 BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb, 1240 struct bpf_map *, map, void *, key, u64, flags) 1241 { 1242 struct sock *sk; 1243 1244 if (unlikely(flags & ~(BPF_F_INGRESS))) 1245 return SK_DROP; 1246 1247 sk = __sock_hash_lookup_elem(map, key); 1248 if (unlikely(!sk || !sock_map_redirect_allowed(sk))) 1249 return SK_DROP; 1250 1251 skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS); 1252 return SK_PASS; 1253 } 1254 1255 const struct bpf_func_proto bpf_sk_redirect_hash_proto = { 1256 .func = bpf_sk_redirect_hash, 1257 .gpl_only = false, 1258 .ret_type = RET_INTEGER, 1259 .arg1_type = ARG_PTR_TO_CTX, 1260 .arg2_type = ARG_CONST_MAP_PTR, 1261 .arg3_type = ARG_PTR_TO_MAP_KEY, 1262 .arg4_type = ARG_ANYTHING, 1263 }; 1264 1265 BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg, 1266 struct bpf_map *, map, void *, key, u64, flags) 1267 { 1268 struct sock *sk; 1269 1270 if (unlikely(flags & ~(BPF_F_INGRESS))) 1271 return SK_DROP; 1272 1273 sk = __sock_hash_lookup_elem(map, key); 1274 if (unlikely(!sk || !sock_map_redirect_allowed(sk))) 1275 return SK_DROP; 1276 1277 msg->flags = flags; 1278 msg->sk_redir = sk; 1279 return SK_PASS; 1280 } 1281 1282 const struct bpf_func_proto bpf_msg_redirect_hash_proto = { 1283 .func = bpf_msg_redirect_hash, 1284 .gpl_only = false, 1285 .ret_type = RET_INTEGER, 1286 .arg1_type = ARG_PTR_TO_CTX, 1287 .arg2_type = ARG_CONST_MAP_PTR, 1288 .arg3_type = ARG_PTR_TO_MAP_KEY, 1289 .arg4_type = ARG_ANYTHING, 1290 }; 1291 1292 struct sock_hash_seq_info { 1293 struct bpf_map *map; 1294 struct bpf_shtab *htab; 1295 u32 bucket_id; 1296 }; 1297 1298 static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info, 1299 struct bpf_shtab_elem *prev_elem) 1300 { 1301 const struct bpf_shtab *htab = info->htab; 1302 struct bpf_shtab_bucket *bucket; 1303 struct bpf_shtab_elem *elem; 1304 struct hlist_node *node; 1305 1306 /* try to find next elem in the same bucket */ 1307 if (prev_elem) { 1308 node = rcu_dereference(hlist_next_rcu(&prev_elem->node)); 1309 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node); 1310 if (elem) 1311 return elem; 1312 1313 /* no more elements, continue in the next bucket */ 1314 info->bucket_id++; 1315 } 1316 1317 for (; info->bucket_id < htab->buckets_num; info->bucket_id++) { 1318 bucket = &htab->buckets[info->bucket_id]; 1319 node = rcu_dereference(hlist_first_rcu(&bucket->head)); 1320 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node); 1321 if (elem) 1322 return elem; 1323 } 1324 1325 return NULL; 1326 } 1327 1328 static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos) 1329 __acquires(rcu) 1330 { 1331 struct sock_hash_seq_info *info = seq->private; 1332 1333 if (*pos == 0) 1334 ++*pos; 1335 1336 /* pairs with sock_hash_seq_stop */ 1337 rcu_read_lock(); 1338 return sock_hash_seq_find_next(info, NULL); 1339 } 1340 1341 static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1342 __must_hold(rcu) 1343 { 1344 struct sock_hash_seq_info *info = seq->private; 1345 1346 ++*pos; 1347 return sock_hash_seq_find_next(info, v); 1348 } 1349 1350 static int sock_hash_seq_show(struct seq_file *seq, void *v) 1351 __must_hold(rcu) 1352 { 1353 struct sock_hash_seq_info *info = seq->private; 1354 struct bpf_iter__sockmap ctx = {}; 1355 struct bpf_shtab_elem *elem = v; 1356 struct bpf_iter_meta meta; 1357 struct bpf_prog *prog; 1358 1359 meta.seq = seq; 1360 prog = bpf_iter_get_info(&meta, !elem); 1361 if (!prog) 1362 return 0; 1363 1364 ctx.meta = &meta; 1365 ctx.map = info->map; 1366 if (elem) { 1367 ctx.key = elem->key; 1368 ctx.sk = elem->sk; 1369 } 1370 1371 return bpf_iter_run_prog(prog, &ctx); 1372 } 1373 1374 static void sock_hash_seq_stop(struct seq_file *seq, void *v) 1375 __releases(rcu) 1376 { 1377 if (!v) 1378 (void)sock_hash_seq_show(seq, NULL); 1379 1380 /* pairs with sock_hash_seq_start */ 1381 rcu_read_unlock(); 1382 } 1383 1384 static const struct seq_operations sock_hash_seq_ops = { 1385 .start = sock_hash_seq_start, 1386 .next = sock_hash_seq_next, 1387 .stop = sock_hash_seq_stop, 1388 .show = sock_hash_seq_show, 1389 }; 1390 1391 static int sock_hash_init_seq_private(void *priv_data, 1392 struct bpf_iter_aux_info *aux) 1393 { 1394 struct sock_hash_seq_info *info = priv_data; 1395 1396 bpf_map_inc_with_uref(aux->map); 1397 info->map = aux->map; 1398 info->htab = container_of(aux->map, struct bpf_shtab, map); 1399 return 0; 1400 } 1401 1402 static void sock_hash_fini_seq_private(void *priv_data) 1403 { 1404 struct sock_hash_seq_info *info = priv_data; 1405 1406 bpf_map_put_with_uref(info->map); 1407 } 1408 1409 static u64 sock_hash_mem_usage(const struct bpf_map *map) 1410 { 1411 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); 1412 u64 usage = sizeof(*htab); 1413 1414 usage += htab->buckets_num * sizeof(struct bpf_shtab_bucket); 1415 usage += atomic_read(&htab->count) * (u64)htab->elem_size; 1416 return usage; 1417 } 1418 1419 static const struct bpf_iter_seq_info sock_hash_iter_seq_info = { 1420 .seq_ops = &sock_hash_seq_ops, 1421 .init_seq_private = sock_hash_init_seq_private, 1422 .fini_seq_private = sock_hash_fini_seq_private, 1423 .seq_priv_size = sizeof(struct sock_hash_seq_info), 1424 }; 1425 1426 BTF_ID_LIST_SINGLE(sock_hash_map_btf_ids, struct, bpf_shtab) 1427 const struct bpf_map_ops sock_hash_ops = { 1428 .map_meta_equal = bpf_map_meta_equal, 1429 .map_alloc = sock_hash_alloc, 1430 .map_free = sock_hash_free, 1431 .map_get_next_key = sock_hash_get_next_key, 1432 .map_update_elem = sock_map_update_elem, 1433 .map_delete_elem = sock_hash_delete_elem, 1434 .map_lookup_elem = sock_hash_lookup, 1435 .map_lookup_elem_sys_only = sock_hash_lookup_sys, 1436 .map_release_uref = sock_hash_release_progs, 1437 .map_check_btf = map_check_no_btf, 1438 .map_mem_usage = sock_hash_mem_usage, 1439 .map_btf_id = &sock_hash_map_btf_ids[0], 1440 .iter_seq_info = &sock_hash_iter_seq_info, 1441 }; 1442 1443 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map) 1444 { 1445 switch (map->map_type) { 1446 case BPF_MAP_TYPE_SOCKMAP: 1447 return &container_of(map, struct bpf_stab, map)->progs; 1448 case BPF_MAP_TYPE_SOCKHASH: 1449 return &container_of(map, struct bpf_shtab, map)->progs; 1450 default: 1451 break; 1452 } 1453 1454 return NULL; 1455 } 1456 1457 static int sock_map_prog_lookup(struct bpf_map *map, struct bpf_prog ***pprog, 1458 u32 which) 1459 { 1460 struct sk_psock_progs *progs = sock_map_progs(map); 1461 1462 if (!progs) 1463 return -EOPNOTSUPP; 1464 1465 switch (which) { 1466 case BPF_SK_MSG_VERDICT: 1467 *pprog = &progs->msg_parser; 1468 break; 1469 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) 1470 case BPF_SK_SKB_STREAM_PARSER: 1471 *pprog = &progs->stream_parser; 1472 break; 1473 #endif 1474 case BPF_SK_SKB_STREAM_VERDICT: 1475 if (progs->skb_verdict) 1476 return -EBUSY; 1477 *pprog = &progs->stream_verdict; 1478 break; 1479 case BPF_SK_SKB_VERDICT: 1480 if (progs->stream_verdict) 1481 return -EBUSY; 1482 *pprog = &progs->skb_verdict; 1483 break; 1484 default: 1485 return -EOPNOTSUPP; 1486 } 1487 1488 return 0; 1489 } 1490 1491 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, 1492 struct bpf_prog *old, u32 which) 1493 { 1494 struct bpf_prog **pprog; 1495 int ret; 1496 1497 ret = sock_map_prog_lookup(map, &pprog, which); 1498 if (ret) 1499 return ret; 1500 1501 if (old) 1502 return psock_replace_prog(pprog, prog, old); 1503 1504 psock_set_prog(pprog, prog); 1505 return 0; 1506 } 1507 1508 int sock_map_bpf_prog_query(const union bpf_attr *attr, 1509 union bpf_attr __user *uattr) 1510 { 1511 __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids); 1512 u32 prog_cnt = 0, flags = 0, ufd = attr->target_fd; 1513 struct bpf_prog **pprog; 1514 struct bpf_prog *prog; 1515 struct bpf_map *map; 1516 struct fd f; 1517 u32 id = 0; 1518 int ret; 1519 1520 if (attr->query.query_flags) 1521 return -EINVAL; 1522 1523 f = fdget(ufd); 1524 map = __bpf_map_get(f); 1525 if (IS_ERR(map)) 1526 return PTR_ERR(map); 1527 1528 rcu_read_lock(); 1529 1530 ret = sock_map_prog_lookup(map, &pprog, attr->query.attach_type); 1531 if (ret) 1532 goto end; 1533 1534 prog = *pprog; 1535 prog_cnt = !prog ? 0 : 1; 1536 1537 if (!attr->query.prog_cnt || !prog_ids || !prog_cnt) 1538 goto end; 1539 1540 /* we do not hold the refcnt, the bpf prog may be released 1541 * asynchronously and the id would be set to 0. 1542 */ 1543 id = data_race(prog->aux->id); 1544 if (id == 0) 1545 prog_cnt = 0; 1546 1547 end: 1548 rcu_read_unlock(); 1549 1550 if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)) || 1551 (id != 0 && copy_to_user(prog_ids, &id, sizeof(u32))) || 1552 copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt))) 1553 ret = -EFAULT; 1554 1555 fdput(f); 1556 return ret; 1557 } 1558 1559 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link) 1560 { 1561 switch (link->map->map_type) { 1562 case BPF_MAP_TYPE_SOCKMAP: 1563 return sock_map_delete_from_link(link->map, sk, 1564 link->link_raw); 1565 case BPF_MAP_TYPE_SOCKHASH: 1566 return sock_hash_delete_from_link(link->map, sk, 1567 link->link_raw); 1568 default: 1569 break; 1570 } 1571 } 1572 1573 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock) 1574 { 1575 struct sk_psock_link *link; 1576 1577 while ((link = sk_psock_link_pop(psock))) { 1578 sock_map_unlink(sk, link); 1579 sk_psock_free_link(link); 1580 } 1581 } 1582 1583 void sock_map_unhash(struct sock *sk) 1584 { 1585 void (*saved_unhash)(struct sock *sk); 1586 struct sk_psock *psock; 1587 1588 rcu_read_lock(); 1589 psock = sk_psock(sk); 1590 if (unlikely(!psock)) { 1591 rcu_read_unlock(); 1592 saved_unhash = READ_ONCE(sk->sk_prot)->unhash; 1593 } else { 1594 saved_unhash = psock->saved_unhash; 1595 sock_map_remove_links(sk, psock); 1596 rcu_read_unlock(); 1597 } 1598 if (WARN_ON_ONCE(saved_unhash == sock_map_unhash)) 1599 return; 1600 if (saved_unhash) 1601 saved_unhash(sk); 1602 } 1603 EXPORT_SYMBOL_GPL(sock_map_unhash); 1604 1605 void sock_map_destroy(struct sock *sk) 1606 { 1607 void (*saved_destroy)(struct sock *sk); 1608 struct sk_psock *psock; 1609 1610 rcu_read_lock(); 1611 psock = sk_psock_get(sk); 1612 if (unlikely(!psock)) { 1613 rcu_read_unlock(); 1614 saved_destroy = READ_ONCE(sk->sk_prot)->destroy; 1615 } else { 1616 saved_destroy = psock->saved_destroy; 1617 sock_map_remove_links(sk, psock); 1618 rcu_read_unlock(); 1619 sk_psock_stop(psock); 1620 sk_psock_put(sk, psock); 1621 } 1622 if (WARN_ON_ONCE(saved_destroy == sock_map_destroy)) 1623 return; 1624 if (saved_destroy) 1625 saved_destroy(sk); 1626 } 1627 EXPORT_SYMBOL_GPL(sock_map_destroy); 1628 1629 void sock_map_close(struct sock *sk, long timeout) 1630 { 1631 void (*saved_close)(struct sock *sk, long timeout); 1632 struct sk_psock *psock; 1633 1634 lock_sock(sk); 1635 rcu_read_lock(); 1636 psock = sk_psock_get(sk); 1637 if (unlikely(!psock)) { 1638 rcu_read_unlock(); 1639 release_sock(sk); 1640 saved_close = READ_ONCE(sk->sk_prot)->close; 1641 } else { 1642 saved_close = psock->saved_close; 1643 sock_map_remove_links(sk, psock); 1644 rcu_read_unlock(); 1645 sk_psock_stop(psock); 1646 release_sock(sk); 1647 cancel_delayed_work_sync(&psock->work); 1648 sk_psock_put(sk, psock); 1649 } 1650 1651 /* Make sure we do not recurse. This is a bug. 1652 * Leak the socket instead of crashing on a stack overflow. 1653 */ 1654 if (WARN_ON_ONCE(saved_close == sock_map_close)) 1655 return; 1656 saved_close(sk, timeout); 1657 } 1658 EXPORT_SYMBOL_GPL(sock_map_close); 1659 1660 static int sock_map_iter_attach_target(struct bpf_prog *prog, 1661 union bpf_iter_link_info *linfo, 1662 struct bpf_iter_aux_info *aux) 1663 { 1664 struct bpf_map *map; 1665 int err = -EINVAL; 1666 1667 if (!linfo->map.map_fd) 1668 return -EBADF; 1669 1670 map = bpf_map_get_with_uref(linfo->map.map_fd); 1671 if (IS_ERR(map)) 1672 return PTR_ERR(map); 1673 1674 if (map->map_type != BPF_MAP_TYPE_SOCKMAP && 1675 map->map_type != BPF_MAP_TYPE_SOCKHASH) 1676 goto put_map; 1677 1678 if (prog->aux->max_rdonly_access > map->key_size) { 1679 err = -EACCES; 1680 goto put_map; 1681 } 1682 1683 aux->map = map; 1684 return 0; 1685 1686 put_map: 1687 bpf_map_put_with_uref(map); 1688 return err; 1689 } 1690 1691 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux) 1692 { 1693 bpf_map_put_with_uref(aux->map); 1694 } 1695 1696 static struct bpf_iter_reg sock_map_iter_reg = { 1697 .target = "sockmap", 1698 .attach_target = sock_map_iter_attach_target, 1699 .detach_target = sock_map_iter_detach_target, 1700 .show_fdinfo = bpf_iter_map_show_fdinfo, 1701 .fill_link_info = bpf_iter_map_fill_link_info, 1702 .ctx_arg_info_size = 2, 1703 .ctx_arg_info = { 1704 { offsetof(struct bpf_iter__sockmap, key), 1705 PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY }, 1706 { offsetof(struct bpf_iter__sockmap, sk), 1707 PTR_TO_BTF_ID_OR_NULL }, 1708 }, 1709 }; 1710 1711 static int __init bpf_sockmap_iter_init(void) 1712 { 1713 sock_map_iter_reg.ctx_arg_info[1].btf_id = 1714 btf_sock_ids[BTF_SOCK_TYPE_SOCK]; 1715 return bpf_iter_reg_target(&sock_map_iter_reg); 1716 } 1717 late_initcall(bpf_sockmap_iter_init); 1718